Emission dynamics from doped crystals of (CH3)4NMnBr3(TMMB)-exciton trapping in a one-dimensional lattice

Abstract

The red emission from (CH3)4NMnBr3 (TMMB) crystals is quenched by small concentrations of Cu2+. The emission decay curves from TMMB crystals doped with Cu2+ deviate dramatically from simple exponential form. Consistent with the linear chain structure of TMMB, the decay curves are accurately described by expressions derived to treat exciton trapping in a one-dimensional lattice. The analysis of the data indicate that the intrachain exciton migration is rapid, with a hopping frequency at room temperature of 1011 to 1012 s−1. The temperature dependence of the emission decay curves is consistent with an energy barrier to migration of 600 to 700 cm−1. Interchain migration apparently makes a negligible contribution to exciton trapping in TMMB with the interchain hopping frequency estimated to be less than 102 s−1. Within the limits of the experimental data, energy transport in TMMB is perfectly one-dimensional.